1. Field of the Invention
The invention relates to a stacked structure of an image sensor, and more particularly to an image sensor in which one of various integrated circuits with different functions and a photosensitive chip may be integrally packaged into a package body so that the material for the package substrate may be reduced.
2. Description of the Related Art
A general sensor is used for sensing signals that may be image signals or audio signals. The sensor of the invention is used to receive image (optical) signals and convert the image signals into electrical signals that are to be transmitted to a printed circuit board.
The image sensor is further electrically connected to other packaged integrated circuits in order to possess various functions. For example, the image sensor may be electrically connected to a digital signal processor which is used to process the signals generated by the image sensor. Furthermore, the image sensor may be electrically connected to a micro controller or a central processing unit to possess various functions.
However, a conventional image sensor is individually packaged. Thus, various integrated circuits mating with the image sensor have to be individually packaged with the image sensor. The packaged image sensor and various signal processing units are then electrically connected to the printed circuit board via a plurality of wires. In this structure, a substrate and a package body have to be used when each of the signal processing units and the image sensor are individually packaged, thereby increasing the manufacturing costs. Furthermore, when each of the signal processing units is mounted to the printed circuit board, the required area of the printed circuit board is relatively large. Thus, the products cannot be made thin, small, and light.
An object of the invention is to provide a stacked structure of an image sensor, in which the number of package members may be reduced, and the package cost may be lowered.
Another object of the invention is to provide a stacked structure of an image sensor, in which the manufacturing processes may be simplified and facilitated.
Still another object of the invention is to provide a stacked structure of an image sensor capable of reducing the area of the image sensor product.
Yet still another object of the invention is to provide a stacked structure of an image sensor capable of lowering the package and test costs of the image sensor product.
To achieve the above-mentioned objects, the invention provides a stacked structure of an image sensor to be mounted to a printed circuit board. The image sensor includes a substrate, an integrated circuit, a frame layer, a photosensitive chip, a plurality of wires, and a transparent layer. The substrate is composed of a plurality of metal sheets arranged in a matrix, and a middle board positioned in a central region surrounded by the metal sheets. Each of the plurality of metal sheets has a first board and a second board positioned at a different height from that of the first board. A slot is formed under the substrate. The integrated circuit is arranged within the slot under the substrate and electrically connected to the substrate. The frame layer surrounds the substrate and the integrated circuit. The first boards and second boards are exposed out of the frame layer, and the second boards are electrically connected to the printed circuit board. The photosensitive chip is placed on the middle board of the substrate. The wires electrically connect the first boards to the photosensitive chip. The transparent layer is placed on the frame layer to cover the photosensitive chip.
According to above-mentioned structure, the image sensor and integrated circuit may be integrally packaged.